1. Field of the Invention
The present invention relates to data transfer between computers, and more particularly to a shared data transfer method in which a computer for performing a shared data saving process is selected in accordance with the properties of a plurality of computers using a shared storage area, and to a coupling facility for transferring shared data.
2. Description of the Related Art
U.S. Pat. Nos. 5,754,856 and 5,802,600 disclose a system for transferring messages among computers and a coupling facility CF shared by computers.
It is an object of the present invention to provide a method and system capable of selecting a computer or computers connected to a shared coupling facility for backing up shared data, in accordance with the cost of each computer resource and reliability, and transferring the shared data in multiples in accordance with an importance degree of the shared data.
It is another object of the invention to provide a shared data transfer method and system capable of reducing the number of transfers of shared data between computers, suppressing the use amount of expensive resources, and shortening a data transfer time.
It is still another object of the invention to provide a data recovery system capable of recovering data lost in a computer which originally stored the lost data, in response to a request from another computer connected to the computer.
In order to achieve the above objects of the invention, a computer connected to a plurality of computers, is provided which comprises a storage area for storing data representative of properties of the plurality of computers relative to the computer; a data area for storing data to be used by the plurality of computers; and a program for determining a computer which holds data in the data area in accordance with another request for the data area.
In a shared data transfer method to be executed by a coupling facility connected to a plurality of computers, the coupling facility having a shared storage area shared by the plurality of computers, property information of each computer is stored in the coupling facility, a computer which performs a process of saving data stored in the shared storage area is selected from the plurality of computers in accordance with the property information, the data stored in the shared storage area is transferred to the selected computer, and information representative of a correspondence relation between the transferred data and the selected computer is stored.
As the property information of each computer, the connection type of each computer to the coupling facility may be used.
As the property information of each computer, an interface of an external storage device of each computer may be used.
The coupling facility stores information regarding a correspondence relation between the shared data in the shared storage area and an importance degree of the shared data, selects one or more computers which save the shared data, in accordance with the importance degree of the shared data, and saves the shared data in multiples.
Further, the coupling facility uses a computer fault occurrence frequency as one piece of the property information of each computer, compares a reference value with the computer fault occurrence frequency of the selected computer which saves the shared data, and in accordance with the comparison result, executes a process of saving the shared data.